scholarly journals NEW ASPECTS ON REACTION MECHANISMS IN THE FORMALDEHYDE HISTOFLUORESCENCE METHOD FOR MONOAMINES

1973 ◽  
Vol 21 (1) ◽  
pp. 17-25 ◽  
Author(s):  
ANDERS BJÖRKLUND ◽  
BENGT FALCK ◽  
OLLE LINDVALL ◽  
LEIF-ÅKE SVENSSON
Keyword(s):  
Mass Spectrometry ◽  
Reaction Mechanisms ◽  
Equal Importance ◽  
Freeze Dried ◽  
Subsequent Step ◽  
Fluorescent Products ◽  
Acid Catalyzed ◽  
Protein Models ◽  
Layer Chromatography ◽  
Mechanisms Of Reactions

The mechanisms of reactions underlying the fluorophore formation from indolylethylamines in the Falck-Hillarp histochemical formaldehyde method were investigated with the aid of thin layer chromatography and mass spectrometry of the fluorescent products formed in protein models and freeze-dried tissue. In the reaction of formaldehyde with tryptamine and 5-hydroxytryptamine, the main fluorophores formed were 3,4-dihydro-β-carboline and the 2-methyl-3,4-dihydro-β-carbolinium compound (from tryptamine), and 6-hydroxy-3,4-dihydro-β-carboline and the 2-methyl-6-hydroxy-3,4-dihydro-β-carbolinium compound (from 5-hydroxytryptamine). From these findings, it is concluded that the fluorophore formation in the Falck-Hillarp method proceeds as follows: In the first step of the reaction, the indolylethylamines react with formaldehyde to form low fluorescent 1,2,3,4-tetrahydro-β-carbolines. In a subsequent step, these products are converted to fluorophores in either of two ways: through an autoxidation to 3,4-dihydro-β-carbolines, or through a second, acid-catalyzed reaction with formaldehyde to yield 2-methyl-3,4-dihydro-β-carbolinium compounds. Experiments with radioactive tryptamine indicated that the two alternative fluorophore-forming pathways are of fairly equal importance. The latter of these fluorophore-forming reactions was not previously known, and the interesting properties and implications of this formaldehyde-induced and acid-catalyzed reaction are discussed.

scholarly journals ACID CATALYSIS OF THE FORMALDEHYDE CONDENSATION REACTION FOR A SENSITIVE HISTOCHEMICAL DEMONSTRATION OF TRYPTAMINES AND 3-METHOXYLATED PHENYLETHYLAMINES 2. CHARACTERIZATION OF AMINE FLUOROPHORES AND APPLICATION TO TISSUES

1971 ◽  
Vol 19 (5) ◽  
pp. 286-298 ◽  
Author(s):  
ANDERS BJÖRKLUND ◽  
ANDERS NOBIN ◽  
ULF STENEVI
Keyword(s):  
Fluorescence Spectra ◽  
Condensation Reaction ◽  
Histochemical Demonstration ◽  
Freeze Dried ◽  
Highly Sensitive ◽  
Hcl Gas ◽  
Fluorescent Products ◽  
Acid Catalyzed ◽  
Cryostat Sections

A histochemical fluorescence method is presented in which a controlled activation of the condensation reaction between formaldehyde and certain aromatic monoamines is achieved by the introduction of minute amounts of HCl gas in the formaldehyde reaction vessel. In this way, not only highly reactive catecholamines and 5-hydroxytryptamine but also less reactive compounds, such as tryptamine, 5-methoxytryptamine and 3-methoxylated phenylethylamines which give only weak fluorescence in the noncatalyzed formaldehyde reaction, can be converted into intensely fluorescent products. The acid-catalyzed formaldehyde treatment proved to be a highly sensitive technique for the demonstration of these various monoamines in freeze-dried tissues. The reaction thus proceeded without any observable dislocation of the substances from their cellular stores and the resulting fluorophores were well visible against an essentially dark background. The procedure was successfully, and equally well, applied to whole freeze-dried tissue pieces, to paraffin sections of freeze-dried specimens and to freeze-dried cryostat sections. The fluorescence properties of a large number of phenylethylamine and indolylethylamine fluorophores, formed in the acid-catalyzed formaldehyde reaction, have been investigated microspectrofluorometrically in models and in freeze-dried tissues. The fluorescence spectra of the amine fluorophores were consistent and fully reproducible, making possible the accurate characterization of cellular monoamines with this method.

ANTI-CANCER COMPOUNDS ISOLATED FROM SOFT CORAL SINULARIA CRUCIATA - ALCYONIIDAE

2012 ◽  
pp. 84-89
Author(s):  
Quoc Hung Vo ◽  
Nguyen Phuong Nhi Doan ◽  
Dinh Quynh Phu Nguyen ◽  
Thi Dieu Tram Ho ◽  
Thi Hoai Nguyen
Keyword(s):  
Mass Spectrometry ◽  
Soft Coral ◽  
Normal Phase ◽  
Ionization Mass ◽  
Medical Field ◽  
Bioactive Substances ◽  
Anti Cancer ◽  
The World ◽  
Pure Compounds ◽  
Layer Chromatography

Objectives: Nowadays, bioactive substances isolated from marine organisms which are abundant and varied in Vietnamese sea attracted more and more the attention of scientists in the world and Vietnam as well. We have studied on soft coral Sinularia cruciata – Alcyoniidae, which has never been studied in Vietnam before, to find substances which are useful in medical field, especially in anti-cancer therapy. Materials and method: Specimens of soft coral Sinularia cruciata were collected from Con Co, Quang Tri province in May 2011. Pure compounds were isolated by using Thin Layer Chromatography; Column Chromatography normal phase and inverse phase; Shephadex LH 20. Structures of them were determined by spectral data of Nuclear Magnetic Resonance (NMR), Electrospray Ionization Mass Spectrometry (ESI-MS). Results & Conclusion: Structures of 4 compounds were identified: (1) 5.8-epidioxycholest-6-en-3-ol (2) Cholesterol (3) 1-O-hexadecyl-glycerol (Chimyl alcohol) (4) Glycerol 1-O-octadecyl ether (Batyl alcohol). The substance (1) was demonstrated to have strong anti-cancer effects in previous study. Key words Sinularia cruciata, Alcyoniidae, 5,8-epidioxycholest-6-en-3-ol, soft coral, cancer.

scholarly journals Hydrothermal Pretreatment of Wheat Straw: Effects of Temperature and Acidity on Byproduct Formation and Inhibition of Enzymatic Hydrolysis and Ethanolic Fermentation

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 487
Author(s):  
Dimitrios Ilanidis ◽  
Stefan Stagge ◽  
Leif J. Jönsson ◽  
Carlos Martín
Keyword(s):  
Mass Spectrometry ◽  
Sulfuric Acid ◽  
Wheat Straw ◽  
High Performance ◽  
Enzymatic Saccharification ◽  
Hydrothermal Pretreatment ◽  
Gas Chromatography Mass Spectrometry ◽  
Enzymatic Digestibility ◽  
Acid Catalyzed ◽  
Pretreatment Conditions

Biochemical conversion of wheat straw was investigated using hydrothermal pretreatment, enzymatic saccharification, and microbial fermentation. Pretreatment conditions that were compared included autocatalyzed hydrothermal pretreatment at 160, 175, 190, and 205 °C and sulfuric-acid-catalyzed hydrothermal pretreatment at 160 and 190 °C. The effects of using different pretreatment conditions were investigated with regard to (i) chemical composition and enzymatic digestibility of pretreated solids, (ii) carbohydrate composition of pretreatment liquids, (iii) inhibitory byproducts in pretreatment liquids, (iv) furfural in condensates, and (v) fermentability using yeast. The methods used included two-step analytical acid hydrolysis combined with high-performance anion-exchange chromatography (HPAEC), HPLC, ultra-high performance liquid chromatography-electrospray ionization-triple quadrupole-mass spectrometry (UHPLC-ESI-QqQ-MS), and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Lignin recoveries in the range of 108–119% for autocatalyzed hydrothermal pretreatment at 205 °C and sulfuric-acid-catalyzed hydrothermal pretreatment were attributed to pseudolignin formation. Xylose concentration in the pretreatment liquid increased with temperature up to 190 °C and then decreased. Enzymatic digestibility was correlated with the removal of hemicelluloses, which was almost quantitative for the autocatalyzed hydrothermal pretreatment at 205 °C. Except for the pretreatment liquid from the autocatalyzed hydrothermal pretreatment at 205 °C, the inhibitory effects on Saccharomyces cerevisiae yeast were low. The highest combined yield of glucose and xylose was achieved for autocatalyzed hydrothermal pretreatment at 190 °C and the subsequent enzymatic saccharification that resulted in approximately 480 kg/ton (dry weight) raw wheat straw.

scholarly journals Neonatal Urine Screening Program in the Province of Quebec: Technological Upgrade from Thin Layer Chromatography to Tandem Mass Spectrometry

2021 ◽  
Vol 7 (1) ◽  
pp. 18
Author(s):  
Christiane Auray-Blais ◽  
Michel Boutin ◽  
Pamela Lavoie ◽  
Bruno Maranda
Keyword(s):  
Mass Spectrometry ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Clinical Symptoms ◽  
Screening Program ◽  
Compliance Rate ◽  
Inborn Errors ◽  
Organic Acidurias ◽  
Urine Screening ◽  
Layer Chromatography

The Quebec Neonatal Urine Screening Program was initiated in 1971 with overall screening inception of newborns in 1973. Forty-seven years later, over 3.5 million babies have been screened for up to 25 inborn errors of metabolism divided into two groups: (1) urea cycle disorders and organic acidurias; and (2) disorders of amino acid metabolism and transport. The main goal of this preventive genetic medicine program is the detection of treatable diseases before the onset of clinical symptoms. Urine specimens from 21-day-old babies are collected and dried on filter paper by parents at home. The participation is voluntary with a high compliance rate over the years (~90%). Specimens are analyzed by thin layer chromatography (TLC). The main objective of this evaluative research project was to assess the feasibility of a technological upgrade towards mass spectrometry. A 2.85-min flow injection method was devised, normal values established, and abnormal profiles confirmed using second-tier tests. The validated assays are sensitive, specific, and suitable for populational screening, as well as for high-risk screening laboratories. Triple H syndrome, which would not be detected in newborns by blood screening at two days of age was found to be positive in the urine of an affected patient.

scholarly journals Compound Identification and In Vitro Cytotoxicity of the Supercritical Carbon Dioxide Extract of Papaya Freeze-Dried Leaf Juice

Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 610
Author(s):  
Kooi-Yeong Khaw ◽  
Paul Nicholas Shaw ◽  
Marie-Odile Parat ◽  
Saurabh Pandey ◽  
James Robert Falconer
Keyword(s):  
Mass Spectrometry ◽  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Chemical Constituents ◽  
Gas Chromatography Mass Spectrometry ◽  
Cytotoxic Activities ◽  
Compound Identification ◽  
Freeze Dried ◽  
Leaf Juice ◽  
Supercritical Carbon

Carica papaya leaves are used as a remedy for the management of cancer. Freeze-dried C. papaya leaf juice was extracted using a supercritical fluid extraction system. Compound identification was carried out using analytical techniques including liquid chromatography coupled to high-resolution quadrupole time-of-flight mass spectrometry (LC–QToF-MS) and gas chromatography–mass spectrometry (GC–MS). The cytotoxic activities of the scCO2 extract and its chemical constituents were determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on squamous cell carcinoma (SCC25) and human keratinocyte (HaCaT) cell lines. The chemical constituents were quantified by QToF-MS. The supercritical carbon dioxide (scCO2) extract of papaya freeze-dried leaf juice showed cytotoxic activity against SCC25. Three phytosterols, namely, β-sitosterol, campesterol, and stigmasterol, together with α-tocopherol, were confirmed to be present in the scCO2 extract. Quantitative analysis showed that β-sitosterol was the major phytosterol present followed by α-tocopherol, campesterol, and stigmasterol. β-Sitosterol and campesterol were active against SCC25 (half maximal inhibitory concentration (IC50) ≈ 1 µM), while stigmasterol was less active (~33 µM) but was biologically more selective against SCC25. Interestingly, an equimolar mixture of phytosterols was not more effective (no synergistic effect was observed) but was more selective than the individual compounds. The compounds identified are likely accountable for at least part of the cytotoxicity and selectivity effects of C. papaya.

Thin-layer chromatography and gas chromatography-mass spectrometry examination of shoe materials from patients with shoe dermatitis

2015 ◽  
Vol 72 (4) ◽  
pp. 248-252 ◽  
Author(s):  
Sri A. Febriana ◽  
Erik Zimerson ◽  
Cecilia Svedman ◽  
Winarto Haryadi ◽  
Pieter-Jan Coenraads ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Gas Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry ◽  
Layer Chromatography
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